Matrix.



M. A. DROITCOUR.

MATRIX.

APPLICATION FILED APR. 9, 1909. RENEWED MAY 12, 1910.

978,824. Patented Dec. 18, 1910.

ame/wlioz UNITED STATES PATENT OFFICE.

MICHAEL A. DROITCOUR, OF CHICAGO, ILLINOIS, ASSIGNOR TO MIEHLE PRINTING PRESS & MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MATRIX.

Patented Dec. 13, 1910.

Application filed April 9, 1909, Serial No. 488,804. Renewed May 12, 1910. Serial No. 560,984.

To all whom it may concern:

Be it known that I, MICHAEL A. DROIT- COUR, a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Matrices,,.of which the followingis a specification.

The .ordinary paste used by stereotypists in the buildin up of papier mach matrices is not well a aptedt to give to the matrices the necessary firmness which will insure its compacting in the line of the pressure which it receives when impressed upon the form without any flowing or spreading outward from such line. I I

One object I have had in view in this in vention has been to devise a aste which would cause thematrix materia to have the necessary or desirable firmness .so that the outward spreading can be avoided.

The ordinary stereotypers paste is also not adapted to use in attaching metal foil such as tin foil as a facing to the impressed surface of the papier mach or the tissue layers with which the apier mach is customarily covered. Nor 1s the ordinary paste adapted to 've the matrices the firmness or rigidity wh1ch they should have to enable them to stand up under the high pressure to which they are subjected in giving impressions to the printing plates I form from them.

Another object I have had in view in this invention has been to devise a paste which would also render the matrix strong and rigid.

My invention consists in the use of .the paste which I desfiibe herein in the building up or preparation of the matrices.

In the manufacture of the matrix in ac- .cordance .with my invention I secure the thicknesses of the paper mach or backing are obtained by uniting these in redients in the proportion of three and one-half ounces of the stereotypers paste and one and onehalf ounces of silicate of soda. The silicate of soda should be added cold to the ordinary stereotypers paste and thoroughly mixed therewith by stirring. Of course, the paste may be used for the-backin as well as the facing, but I do not wish to he limited to the proportions stated. I also use my novel paste in attaching the tin foil.

The tissue facing is applied to the backing is'covered with paste and another sheet of tissue laid thereon; and in this way several sheets are put on to form the proper facing. Then the back of a sheet of tin-foil is covered with the silicate of soda paste and laid on the tissue facing and smoothed. I preferably use a metal roller to iron the facing sheets smoothly as they are applied and to force out any air which might be trapped under the sheets, and thus insure close contact at all points between the sheets of the facing.

By the use of my paste, I not only render the matrix suflioiently firm so that when it is impressed on the form, the type of the latter'force the material inward in the direction of the pressure, instead of forcing it to seek escape by fiowin laterally. It also acts to render the tin foi secure and prevent its becoming detached when the impression is made, and the rigidity of the matrix is increased so that it does not yield under the pressure exerted upon it when printing plates are shaped upon it. p

In'the accompanying drawings Figure 1 illustrates the several parts of the matrix blank before they are united; and Fig. 2 represents the complete matrix blank.

In said figures B represents the backing of blotting paper or any other'suitable material; T the sheets of tissue paper, any desired number of which are pasted to each other and to the backing B with silicate of soda paste as above described; and F a tinfoil 'facin united to the tissuesheets by silicate of so a as above described.

,1. A papier mach matrix blank, compris- V ing a backing of suitable material and a facing composed of a plurality of sheets of tissue paper attached to each other kind to the backing by a paste containing silicate layers of suitable material united by paste, of soda whereby the facing-is adapted toreand a facing of tin foil secured to said 1 tain and preserve fine lines and points in backing by a, paste containing silicate of the intaglio impression in said faclng made soda. 5 by the type surface, and rupture of the fac- 4. A matrix for use in making printing ing is prevented. surfaces, formed of layers of sheets united 2. A matrix for producing printing surbypaste containing silicate of soda, and a g faces consisting of a backing of suitable tin -.foil facing united to said layers by material and a facing of tin foil secured to paste containin silicate of soda.

10 said backingby a paste containing silicate MIC AEL A. DROITCOUR.

of soda. Witnesses: p 3. -A matrix for producing printing sur H. M. MUNDAY,

faces consisting of a backing. formed of ESTHER ABRAMs. 

